The question of whether sound vibration of a medium can bring about any kind of molecular or macromolecular events is a long-standing scientific controversy. Although it is known that ultrasonic vibrations with frequencies of more than 1 MHz are able to align certain macromolecules in solution, no effect has yet been reported with audible sound, the frequency of which is much lower (20-20,000 H...

In seven chronically instrumented conscious dogs, micromanometers measured left ventricular pressure, and ultrasonic dimension transducers measured left ventricular minor-axis diameter; the latter recording was filtered to examine data between 20 and 100 Hz. Acceptable external heart sounds were recorded with a phonocardiographic microphone in four of the seven dogs. With each dog sedated, intu...

In the article, three types of proximity sensors that might be used in bicycle rangefinder to measure distance between and an overtaking car are compared. The influence various factors on accuracy measurements obtained using ultrasonic, infrared laser is tested, among others, light conditions, surface type colour, rain, pollination vibrations.

The ability to noninvasively detect regional dynamic myocardial damage related to action potentials and mechanical properties affected by heart disease is of great clinical importance. Though there are invaluable clinical tools for diagnosis of a broad range of cardiac conditions, such myocardial properties cannot be evaluated. We have previously shown that pulsive vibration occurs on the myoca...

Rock and soil penetration by coring, drilling or abrading is of great importance for a large number of space and earth applications. An Ultrasonic/Sonic Drill/Corer (USDC) has been developed as an adaptable tool for many of these applications [Bar-Cohen et al, 2001]. The USDC uses a novel drive mechanism to transform the ultrasonic or vibrations of the tip of a horn into a sonic hammering of a ...

Dynamic modulus of elasticity was determined in clearwood samples of eight tropical hardwood species using longitudinal vibrations, flexural vibration and ultrasonic transit-time methods. These samples were subsequently subjected to three point static bending test to determine static modulus of elasticity and modulus of rupture. Acoustic velocity and wood density were found to be independent pa...

In this article, application of various methods for evaluating and measuring porous food structures are reviewed. It is noted, that ultrasonic vibrations and waves, due to their physical properties and wide frequency interval, can successfully be applied when analyzing porous food structures. These methods have a lot of advantages when comparing them with other non-acoustic measurement methods....